"Case Sensitive" = False 
"Start Symbol"   = <Lines>

<String Chars>::= {Printable} - ["]
<NewLine>     ::= [CR, LF]+ | [CR]+

<Letter>      ::= [a-zA-Z]
<digit>       ::= [0-9]
<Symbols>     ::= [_-]
<Space>       ::= ' '

<Remark>      ::= REM {Space}* {Printable}*
<Sub ID>      ::= {Letter}+({Letter}?{digit}?{Symbols}?)*
<Type>        ::= [$%!#]
<ID>          ::= <SUB ID> | <Typed ID>
<Typed ID>    ::= <SUB ID><Type>
<ID OR CONST> ::= <Typed ID> | <Constant>

<String>      ::= '"'{String Chars}*'"' 
<Integer>     ::= [-]?{digit}+ 
<Real>        ::= [-]?{digit}+.{digit}+ 

<Lines>       ::= <Line> <NewLine> <Lines>  | <Line>
                 | <Labeled Line> <NewLine> <Lines> | <Labeled Line>

<Line>        ::= <Statements>
<Labeled Line>::= <Integer> <Statements>

<Statements>  ::= <Statement> ':' <Statements> | <Statement>

<Statement>   ::= <Let ID>
                | <Assign ID>
                | GOTO <Integer>
                | <Remark>
                | PRINT <Print list>
                | INPUT <ID List>
                | <Loop>
                | <Array access>
                | <Function>
                | <Call Function>	
   
                
<Array declare> ::= DIM <ID> '(' <Integer List> ')' AS <TYPE>        
<Array access>  ::= <ID> '(' Integer List ')' 
                  | <ID> '(' Integer List ')' '=' <Expression>

<Assign ID>     ::= <ID> '=' <Expression>
<Let ID>        ::= LET <Assign ID>

<If>          ::= IF <Expression> THEN <Lines> <NewLine> <If end>  
                | IF <Expression> THEN <Lines> ELSE <Lines> <NewLine> <If end> 
<If end>      ::= END IF | ':' END IF

<Loop>        ::= <For loop> | <While loop>

<For loop>    ::= FOR <ID> '=' <Expression> TO <Expression> <Lines> <NewLine> <For end>
                | FOR <ID> '=' <Expression> TO <Expression> STEP <Integer> <Lines> <NewLine> <For end>
<For end>     ::= NEXT <ID> | ':' NEXT <ID>

<While loop>  ::= WHILE <Expression> <Lines>  <NewLine>  <While end>
<While end>   ::= WEND | ':' WEND

<Function>    ::= DECLARE Function <ID> '('<FuncArgs List>')'
                | FUNCTION <Typed ID> '('<FuncArgs List>')' <Lines> <NewLine> END FUNCTION

<Call Function> ::= <Typed ID> '(' <Call list> ')'
<Call list> ::= <ID OR CONST> ',' <Call list> | <ID OR CONST>

<TYPE> ::= INTEGER | LONG | SINGLE | DOUBLE | STRING

<ID List>       ::= <Typed ID> ',' <ID List> | <Typed ID> 
<FuncArgs List> ::= <ID List>

<Value List>      ::= <Value> ',' <Value List> 
                | <Value> 

<Constant List>   ::= <Constant> ',' <Constant List> 
                | <Constant> 

<Integer List>    ::= Integer ',' <Integer List>
                | Integer

<Expression List> ::= <Expression> ',' <Expression List> 
                | <Expression> 

<Print List>      ::= <Expression List> ',' <Print List>
                | <Expression> 

<Expression>  ::= <And Exp> OR <Expression> 
                | <And Exp> 

<And Exp>     ::= <Not Exp> AND <And Exp> 
                | <Not Exp> 
 
<Not Exp>     ::= NOT <Compare Exp> 
                | <Compare Exp> 

<Compare Exp> ::= <Add Exp> '='  <Compare Exp> 
                | <Add Exp> '<>' <Compare Exp> 
                | <Add Exp> '>'  <Compare Exp> 
                | <Add Exp> '>=' <Compare Exp> 
                | <Add Exp> '<'  <Compare Exp> 
                | <Add Exp> '<=' <Compare Exp> 
                | <Add Exp> 

<Add Exp>     ::= <Mult Exp> '+' <Add Exp> 
                | <Mult Exp> '-' <Add Exp> 
                | <Mult Exp> 

<Mult Exp>    ::= <Negate Exp> '*' <Mult Exp> 
                | <Negate Exp> '/' <Mult Exp> 
                | <Negate Exp> 

<Negate Exp>  ::= '-' <Value> 
                | <Value> 

<Value>       ::= '(' <Expression> ')'
                | <ID> 
                | <Call Function>
                | <Constant> 

<Constant>    ::= <Integer> 
                | <String> 
                | <Real>